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Today my car suddenly started to overheat when idling. I already trying changing the 2 fuses in the engine bay and the 1 fuse under the dash. I trying switching the horn relay to see if that was the problem. The problem is the radiator fan is not coming on. I tried turning the AC on and one fan will turn when I do so. But when my temp gauge goes past halfway neither fan turns on. Also my temp stays very stable when I’m actually moving. But when idling the temps go up kind of fast, but they also drop pretty fast when I start moving again.

 
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remove the fan and test it using a 12V source. If it spins, check the fan itself off from the list of possible causes
Moved to thread to the overheating section of the forums

 
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wait, from your other thread, you said your overflow tank is full? if so, you need a head gasket

 
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My overfill tank was full because I filled it past the max line, because I thought it was empty. It’s sitting where it should be sitting right now.

 
Rep Power: 367

OK, now I understand what you were saying back then.

What is involved in general (Have not checked if Civics of this gen have anything different, just regular mechanic knowledge)

• Fan itself (can be tested)
• Fan switch (turns the fan on-off) - I think Hondas have the switch/sensor in one unit? not sure
• all the wires in-between

 
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Ok, I’ll check them out thank you.

 
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Problem has been fixed, it was driver’s side fan. Weird thing is, neither fan was turning on when the car was overheating. But after replacing the driver’s side fan both fans turn on to prevent overheating.

Edit: I didn’t find this in any forum post until I came across it on YouTube. You can stick a paper clip in the fan switch connector then turn the power on in the car (don’t start it just turn the key) to make the fans run to help diagnose the problem.

 
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the other fan will turn on if your a/c is turned on

 
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If you turn the ac on the passenger side fan comes on by itself. But when the car needs to cool down both fans turn on. They did for me at least. But neither fan turned on to cool the car off while the driver side fan wasn’t operational.

 
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Driver's side being the right side?
Thats opposite for most of us on here

 
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Driver side being the left side.

 
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didn't look at wiring diagrams to see if both fans are connected somehow, but glad your issue is solved.

 
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My mistake, I was thinking of the 6th gens with the 2 small rads

 
Rep Power: 224

Definitely keep an eye on coolant level just in case the head gasket is leaking as well.